1. Technical Field
The present invention relates to an optical element, an electro-optical device, and a mounted display apparatus.
2. Related Art
In recent years, mounted display apparatus such as head mounted displays have attracted attention. In such head mounted display, adjustment that exactly matches a display position of an image to a position of a pupil becomes necessary if images are smaller than a pupil diameter, and therefore, since usability is worsened, optical elements that enlarge image light beyond the pupil diameter are used. As such an optical element, a technology that enlarges image light by using two diffraction gratings, is known (for example, refer to JP-A-07-72422).
Incidentally, miniaturization is highly regarded in head mounted displays, and the miniaturization of devices has been realized by drawing images on the retina of the eye by scanning with a laser beam. In such an instance, the combined use of the abovementioned optical elements in a laser scanning method has been considered.
However, in a method that scans using a fine laser beam, since the image light becomes considerably small in comparison with pupil diameter, it is difficult to sufficiently enlarge the image light in the abovementioned optical elements. In such an instance, even in a case in which the image light is sufficiently smaller than pupil diameter in the manner of a method that scans with a laser beam, the provision of a new technology that can cause image light to be incident to a pupil is desired.